The present invention relates to electronics assemblies, and is primarily concerned with racked assemblies. Many such assemblies will be located in racks for housing in, for example, nineteen inch cabinets, or other size cabinets such as twenty three inch or metric cabinets. The assemblies may for instance be employed as servers for a number of systems, for example in local area networks (LANs), wide area networks (WANs), telecommunications systems or other operations such as database management or as internet servers.
Such an assembly will typically comprise housing, for example in the form of a supporting chassis that houses a motherboard or backplane and a number of daughterboards or module cards that extend in planes generally perpendicular to the plane of the motherboard. Other components may be included, such as power supply units, hard disc drives, tape drives, ROM drives etc., with the result that the space available for provision of all the services in the enclosure is severely limited, and no internal space of the enclosure can be wasted.
One form of computer that may be used in such an assembly is called a “high RAS computer” that is to say, a computer that needs to provide a high degree of reliability, availability and serviceability. Such computers need to maximise the length of time during which the computer is operational. The computer may need to withstand a considerable degree of vibration, whether to particular office conditions or because of seismic activity, and so needs to exhibit a high degree of ruggedness. Furthermore, any periods during which the computer is down for example due to repair or maintenance should be minimised, which requires reducing the time taken to remove and reinstall any components of the system.